HS2 is much more than just an infrastructure project on a map. Instead, it should be seen as the future backbone of Britain's growing railway, serving the needs of a modern and dynamic economy. As hi-tech and creative industries gravitate to city centres, rail more than ever is key to serving the needs of our major wealth-creating centres.

In fact, demand for rail travel across the network has outstripped economic growth in the past 15 years and is set to continue growing. That is why £38bn is already due to be invested in maintaining and enhancing the existing network over the next five years.

But we need to continue investing in the longer term, both on existing and new lines, just as we are now. Some parts of the west coast mainline between London and the north-west are now so busy that by the mid-2020s they will be full for long periods on key stretches of the route.

So the country faces a choice: we can make further gradual improvements on that route, which will buy us a few years' extra capacity; or – as we, the rail companies operating today's network, believe – we can build a new line as a strategic opportunity to transform the way rail more widely serves the nation.

How a HS2 train might look. 'Prices should be broadly comparable to other parts of the network'. Photograph: PA

The fundamental point to recognise here is that HS2 will serve eight out of 10 of Britain's largest cities and one in five of the UK population. It will also allow for new passenger and freight services to be created between towns and cities not directly linked to the new line.

Towns such as Northampton, Nuneaton and Leighton Buzzard, for example, will receive more trains as HS2 will carry inter-city services currently running on the west coast mainline.

To unlock this generational opportunity and make sure its benefits are spread widely, HS2 needs to be plugged effectively into the existing network, not seen as a stand-alone project. Stations and junctions must be designed and managed to allow passengers and goods to move with ease across both parts of the railway, delivering extra capacity where it is needed.

Equally important is setting fares at the right level. Prices should be broadly comparable with those on other parts of the network to ensure they are affordable and encourage more rail travel on HS2 and across the existing railway. Tickets for HS2 should be sold through the same national retailing outlets as for the existing network to make getting a seat as straight forward as possible.

As well as planning for new and extra services on the existing network as capacity is released once HS2 is up and running, other priorities are developing the specification and procurement of the new train service to operate on the new line and buying the right trains.

Britain's record at running the safest and fastest-growing major railway in Europe, and at building major projects such as the Olympic Park, HS1 and Crossrail, should inspire confidence that we have the expertise and will to address these issues. Parliamentarians should take heart from that as they consider the HS2 bill in the months ahead.